1. Field of the Invention
The present invention relates to a curl removing device for removing a curl from a rolled paper by straining in a direction opposite to a curl direction thereof when deriving the rolled paper from a tray formed in an image forming apparatus such as facsimile machine which utilizes as a print paper the rolled paper in a roll form. In particular, the present invention relates to a curl removing device in which a curl removing plate used therein can be very easily installed in a main body of the image forming apparatus, thereby assembling work thereof can be easily done by simplifying assembling steps.
And the present invention relates to the curl removing device of the rolled paper in which number of parts can be reduced and easily assembled, thereby the cost thereof can be lowered. Further, the present invention relates to the curl removing device of the rolled paper in which clearance among the parts thereof can vanish, thereby uncomfortable noise due to the clearance can be avoided and it can prevent the parts from being broken due to the clearance.
2. Description of Related Art
In general, in the facsimile machine utilizing as the print paper the rolled paper which is rolled around a cylindrical core in a roll form, the curl inevitably occurs in the rolled paper derived from the core, and in case that the curl is not removed from the paper, the paper which is discharged from the facsimile machine after characters transmitted from the other facsimile machine are printed is inevitably curled, thus handling of the received papers becomes very troublesome. To dissolve this problem, it is conventionally proposed various devices for removing the curl from the rolled paper.
For instance, it is disclosed in Japanese Patent Application, Laid Open No. Hei 5-238,617, a curl removing device in which a curl removing plate is fixed on a flange of upper cover in the facsimile machine by screws. In the curl removing device, the rolled paper derived from a tray is strained in a direction opposite to the curl direction thereof through cooperation between the nose part of curl removing plate and the guide bar arranged near the nose part, thereby the curl in the rolled paper is removed.
In the curl removing device disclosed in the above Japanese Patent Application, the curl removing plate is fixed on the flange of upper cover by the screws. In this way, if the curl removing plate is fixed by the screws, fixing work of the curl removing plate to the upper cover becomes very troublesome, therefore assembling work of the curl removing device cannot be easily done.
Thus, in order that assembling of the curl removing plate inside a main body of the facsimile machine can be simply conducted, there exists, for example, a curl removing device shown in FIGS. 9 and 10. Here, it will be described based on FIGS. 9 and 10 the conventional curl removing device in which the curl removing plate can be simply assembled. FIG. 9 is a perspective view schematically showing a relation between the curl removing plate and the plate holding part in the conventional curl removing device. And FIG. 10 is a perspective view schematically showing a state that the curl removing plate is assembled to the plate holding part.
In FIGS. 9 and 10, the plate holding part 100 is formed in the facsimile machine and a pair of holding sections 101 are formed on the plate holding part 100. In each holding section 101, at the same side plane (in FIGS. 9. 10, the right side plane), a support shaft 102 is formed into one body. And a flat plate part 103 is positioned between the holding sections 101. The curl removing plate 104 is formed so as to have a curl removing part 105 having a folded top portion contacting with the rolled paper for removing the curl from the rolled paper by straining the paper in a direction opposite to the curl direction, and a holder part 106 continuously formed from the curl removing part 105 with a predetermined angle and a pair of supporting parts 108 which are formed at both side ends of the curl removing part 105 so as to be positioned at both sides of the holder part 106 and have supporting holes 107 respectively.
When the curl removing device is assembled by installing the curl removing plate 104 to the plate holding part 100, the holder part 106 is slid in the left direction on the flat plate part 103 and each support shaft 102 on the holding section 101 in the plate holding part 100 is fit into the supporting hole 107 formed in each supporting part 108 in the curl removing plate 104. Further, in order not to be produced the clearance in the lateral direction (in FIGS. 9 and 10, the clearance toward the right and left directions) due to that the supporting parts 108 moves along the support shafts 102 while the curl removing plate 104 rotates, the E-ring 109 is set to one of the support shafts 102 and thereby it is prevented the clearance between the holding section 101 and the supporting part 108 from producing. According to the above, the curl removing device shown in FIG. 10 is assembled. In the thus assembled curl removing device, it is not necessary to fasten the curl removing plate 104 by the screws, different from the curl removing device disclosed in Japanese Patent Application explained above, and the curl removing plate 104 can be comparatively easily assembled to the plate holding part 100.
However, in the curl removing device shown in FIGS. 9 and 10, it is utilized the E-ring 109 to vanish the clearance produced due to movement of each supporting part 108 in the curl removing plate 104 along the support shaft 102. At this time, it is necessary to conduct setting work of the E-ring 109 to the support shaft 102 within very narrow space and to use special jig for the E-ring 109. Therefore, setting work of the E-ring 109 to the support shaft 102 is very troublesome and difficult.
Further, in the above curl removing device, though assembling of the curl removing plate 104 to the plate holding part 100 is comparative easily done, it is necessary to set the E-ring 109 to the support shaft 102, thus number of assembling steps increases due to setting work of the E-ring 109 and assembling cost of the curl removing device is increased.
Next, another conventional curl removing device will be described with reference to FIG. 11. FIG. 11 is a side sectional view partially showing the curl removing device which is enlarged. The curl removing device 140 is utilized for the facsimile machine.
In the curl removing device 140, a bearing member 142 having an elliptical hole 142A is formed on lower surface of a upper cover 141 and a round shaft 143 made of iron is inserted in the bearing member 142. When the upper cover 141 is rotated around a rotating shaft 144 in the direction that the upper cover 141 covers upper space of a platen 145 and a recording head 146, that is, in the direction shown by an arrow C in FIG. 11, the shaft 143 is moved in the right direction in FIG. 11 within the hole 142A of the bearing member 142 by means of a shaft catch member 148 which is arranged to a print frame 147 and has a guide surface inclined in the right lower direction. Finally, the shaft 143 is caught in a catch groove of the shaft catch member 148 while the shaft 143 is faced to a curl removing plate 149 installed to the print frame 147, as shown in FIG. 11. The folded portion 149A of the curl removing plate 149 is arranged so as to face toward a rolled paper 150 and the shaft 143 caught by the shaft catch member 148 is arranged close against the curl removing plate 149, thereby it is formed a feeding path of the rolled paper 150, the feeding path being bent in the direction opposite to the curl direction of the rolled paper 150. Thus, when the rolled paper 150 derived from a tray 151 is passed through the feeding path, the curl of the rolled paper 150 is removed.
However, in the above curl removing device 140, to form the bent path in the direction opposite to the curl direction of the rolled paper 150, many parts such as the upper cover 141, the bearing member 142, the shaft 143, the shaft catch member 148 and the curl removing plate 149 are necessitated. Thus, there is a problem that assembling steps and parts for the curl removing device increase and the cost thereof also increases. And steps for inserting the shaft 143 into the bearing member 142 formed in the upper cover 141 and fixing the shaft 143 in the bearing member 142 so as not to come off by, for example, a stop ring are very troublesome, thereby it concludes to take a considerable long time for such steps. Therefore, there is a problem that the cost of the curl removing device further increases due to the above steps.
And however, in the above curl removing device 140, the shaft 143 used for forming the feeding path of the rolled paper 150 is inserted into the elliptical hole 142A formed in the bearing member 142, thus there occurs a problem that it inevitably produces a clearance between the shaft 143 inserted in the shaft catch member 148 and the bearing member 142. Based on the clearance, while the facsimile machine with the above curl removing device 140 is transported, collision between the iron shaft 143 and the bearing member 142 made of synthetic resin is repeated due to oscillation occurring while transportation. As a result, there is a problem that uncomfortable noise produces due to the clearance and the bearing member 142 is broken.